1. Field of the Invention
The present invention relates to a dryer which is mounted in a housing. The dryer includes a precision balance arranged in the housing for determining the moisture content of material to be weighed which is placed on a weighing dish and is subjected to heat radiation from a heat source of the dryer. For making the material to be weighed accessible, the weighing dish can be moved in and out of the housing.
2. Description of the Related Art
A dryer with a precision balance mounted in the dryer for determining the moisture content of the material to be weighed is disclosed in prior application Ser. No. 08/163,925, now U.S. Pat. No. 5,485,684. The measuring cell of the precision balance with the weighing dish mounted thereon is constructed in such a way that it can be moved in and out of the housing for charging and weighing-in of the material to be weighed. In the moved-in state of the weighing dish, a heat source is mounted in the housing above the weighing dish, wherein the heat radiation of the heat source is transmitted directly from above onto the material to be weighed placed on the weighing dish. A cover glass for protecting the heat source against contamination may be mounted between the material to be weighed and the heat source.
When working with the known dryer, it is not possible to prevent the heat radiation of the heat source from not only heating the material to be weighed but also additional components which are within the range of radiation of the heat source. These components are particularly the weighing dish and the measuring cell of the precision balance as well as the protective cover glass between the heat source and the weighing dish. Errors of measurement may occur because of heating of the measuring cell due to the high temperatures.